Mankind is dependent upon field crops for food, fiber, animal feed and the like. The ever increasing world population dictates the necessity to produce more from each hectare and, at the same time, to preserve and protect the environment and natural resources that make such production a possibility. Successful crop production and environmental concerns have led professional agriculturalists to implement pest management practices.
Good pest management practices include resistance management practice, i.e. combining herbicides with other herbicides having a different mode of action and combining herbicides with other weed-control techniques. The extensive and continued use of herbicides has lead to important weed resistance problems. Therefore, herbicides of varying modes of action are being used in combinations, applied separately or together, as an integral part of a broad, overall weed-control program tailored to reduce herbicide use rates, enhance the spectrum of weed control, prevent resistant weed species and reduce energy and fuel expenditures.
However, in actual practice, the simultaneous or sequential application of two or more herbicides may result in an undesirable interaction of a biological nature, such as altering the selectivity of the herbicide or decreasing the efficacy of the herbicide. Herbicide interactions are generally categorized as additive, synergistic or antagonistic. The interactions are described as synergistic when the net effect is an enhancement of biological activity and antagonistic when the net effect is a decrease in the biological activity. In other words, an antagonistic interaction of a herbicide combination is a less than additive toxic action of two or more herbicides when used together. Herbicide combination applications which result in an antagonistic interaction are herein described as antagonistic herbicide combinations.
Antagonistic herbicide combinations can increase weed-crop competition and the risk of weeds growing unchecked in periods of adverse weather or soil conditions resulting in reduced crop yields and crop quality and enhanced production and harvest costs.
Therefore, it is an object of this invention to protect vide a method to overcome the antagonistic interaction of herbicide combinations.
It is another object of this invention to provide a method to improve the weed control of antagonistic herbicide combinations used in resistance management practice.
It is a further object of this invention to provide compositions of herbicide combinations useful for improved weed control.
These and other objects and features of the invention will become apparent from the detailed description set forth below.